Which of the following is true about displayed formulas?

Displayed formulas are a way of representing the molecular structure of a compound by illustrating how atoms are bonded together. In displayed formulas, every atom is shown as its chemical symbol, and the bonds between them, such as single or double bonds, are depicted with straight lines. This allows one to visualize the connectivity between different atoms, including the nature of the bonds formed.

The correct choice indicates that displayed formulas depict the relationships between atoms, including bond angles. While displayed formulas primarily show the actual atoms and their bonds, they implicitly suggest the geometry of the molecule. Although bond angles are not always explicitly represented in two-dimensional drawings, the connectivity and arrangement inherently influence the spatial orientation of the atoms, reflecting the molecular geometry. This geometrical insight is crucial for understanding how molecules interact and behave in different environments.

The other options do not accurately capture the purpose or characteristics of displayed formulas. They do not provide 3D representations, nor are they limited to just indicating the types of atoms or exclusively used for aromatic compounds. Instead, displayed formulas are versatile and applicable to a wide range of molecules, including aliphatic and aromatic compounds, providing detailed insight into the structure and bonding within the molecule.